Can anyone help me with this challenge. I have an amortization
schedule calculating mortgages. Everything works fine except that I
would like to add a feature for interval extra payments. Does anyone
know how to do this?



Based on a date, insert pmt in a cell depending on the interval that
was decided.



Ex:



No. Due Date Payment Due Principal Additional Payment Interest
Balance

1 03/07/2008 1,270.51 218.76 1,270.51 1,051.75 249,083.73
2 04/07/2008 1,270.51 225.01 1,270.51 1,045.50 247,588.21
3 05/07/2008 1,270.51 231.29 1,270.51 1,039.22 246,086.41
4 06/07/2008 1,270.51 237.59 1,270.51 1,032.92 244,578.31
5 07/07/2008 1,270.51 243.92 1,270.51 1,026.59 243,063.88
6 08/07/2008 1,270.51 250.28 1,270.51 1,020.23 241,543.09
7 09/07/2008 1,270.51 256.66 1,270.51 1,013.85 240,015.92
8 10/07/2008 1,270.51 263.07 1,270.51 1,007.44 238,482.34




I would like to add an additional payment only every 2 months and not
every months.



Cheers,



Jagaude